Hi I have resently bought a 560SEL and the cabin heater only blows hot regardless of what the heat dials are set too!!! anyone anyanswers ????

 

The failure mode of the ccu (climate control unit) is heat on. It could be the mono valve (turns on hot water to cabin) that is controlled by the ccu or vacuum valves or the elec part of the ccu. You need a manual to see where to start checking. CD copies are sold by some board members and on ebay for $20 or so. Good luck.

 

The manual on CD is also sold by Mercedes for $20.